According to Royal Jordanian Airlines, the TSA sent out an email unveiling a new rule (effective tomorrow) that passengers on flights “originating from 13 nations” will no longer be allowed to carry electronic devices larger than a cellphone into airline cabins—they must put those items into checked baggage. This includes laptops, tablets, cameras, DVD players, and electronic gaming devices.

Here’s a screenshot of the tweet (which has since been deleted):

We still don’t know yet the exact why (there’s supposedly a ‘terrorism threat’ related to the new TSA rule announced tomorrow), or what airlines from those 13 countries are participating in the electronics ban (though according to the Guardian, they include Royal Jordanian Airlines and Saudi Arabia’s Saudia Airlines).

While it remains unclear as to whether this order is related to Trump's travel ban of Muslim-majority countries, there’s also been incidents where phones like the Samsung Galaxy Note 7 have been banned from flights due to their tendency to…explode on people.

UPDATE: The full list of cities and countries where the ban on electronic devices will be in effect on inbound flights to the U.S. include: Cairo, Egypt; Dubai and Abu Dhabi, United Arab Emirates; Istanbul, Turkey; Doha, Qatar; Amman, Jordan; Kuwait City; Casablanca, Morocco; and Jeddah and Riyadh, Saudi Arabia.

From the Department of Homeland Security:

"Evaluated intelligence indicates that terrorist groups continue to target commercial aviation and are aggressively pursuing innovative methods to undertake their attacks, to include smuggling explosive devices in various consumer items....we have reason to be concerned about attempts by terrorist groups to circumvent aviation security and terrorist groups continue to target aviation interests. Implementing additional security measures enhances our ability to mitigate further attempts against the overseas aviation industry."

The U.K. has also implemented this ban, though a specific terror threat is not cited in their announcement.